1. Field of the Invention
The present invention relates to an image reading and recording apparatus including a recording head that records an image on a recording sheet and a reading unit that reads an image of a document.
2. Description of the Related Art
Typical recording apparatuses record an image (including characters and symbols) on a recording medium, such as a sheet of paper, a cloth, a plastic sheet, and an overhead transparency, (hereinafter, referred to as a recording sheet) based on recording information. Recording apparatuses can be classified into the ink jet type, the wire dot type, the thermal type, and the laser beam type, depending on their recording processes.
A serial recording apparatus, which records information while main-scanning a recording sheet in a direction orthogonal to the direction of conveying the recording sheet, records an image using a recording head mounted on a carriage moving along the recording sheet. The serial recording apparatus completes recording on the entire recording sheet by repeating a recording operation for a line, a paper feeding operation by a predetermined amount after the completion of the recording operation, and a next recording operation for the next line. In contrast, a line recording apparatus, which records information by only sub-scanning a recording sheet in the direction of conveying the recording sheet, completes recording on the entire sheet by repeating a set operation of setting a recording sheet at a predetermined record position, a recording operation of recording an entire line at a time, a paper feeding operation by a predetermined amount, and a next recording operation of recording a next entire line at a time.
An image reading and recording apparatus including a recording unit that records an image on a fed recording sheet and a reading unit that reads a fed document is used. Japanese Patent Laid-Open No. 2005-354453 discloses an image reading and recording apparatus that includes a common unit used as both a paper feed unit and a conveying unit for a recording sheet and a document to reduce costs and size. This patent document discloses a technique for being able to feed a recording sheet and a document when a carriage is in a predetermined position using the ink jet recording process of recording information by discharging ink droplets from a recording head mounted on the carriage.
Unfortunately, for the image reading and recording apparatus described in this patent document, the carriage is at rest in the same position both when a recording sheet is fed and when a document is fed. In addition, because this image reading and recording apparatus uses the ink jet recording process, the recording head is capped in a standby state by a cap disposed at a position for maintenance of the recording head. The recording apparatus having this structure feeds a sheet of paper in a state in which the cap is separated from the recording head (in a cap-open state). The recording apparatus having this structure is also in a cap-open state during a document feeding operation, when a recording operation is not performed. As a result, maintenance operations, such as discharging of ink from the recording head or cleaning of the recording head by wiping after such a feeding operation, are needed.
In the image reading and recording apparatus described in the patent document, a discharge recovering portion (maintenance portion) is driven using a reverse drive of a conveying motor. For such an image reading and recording apparatus, even when the recording head is capped immediately after the completion of a paper feeding operation, a suction pump of the discharge recovering portion is actuated simultaneously with a reverse rotation of a conveying roller to locate the beginning of a document or for other purposes during a document feeding operation. This may inadvertently apply a negative pressure to an ink discharging portion of the recording head.
One approach to avoiding such a disadvantage is to repeat maintaining the cap-open state until a paper feeding operation or an operation of locating the beginning of a document is completed for each page. However, for this approach, ink in an opened discharge port is apt to be dried and fixed.